<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
	<script>
		// Object.defineProperty(Object.prototype,'aaaa',{
		// 	enumerable:false
		// })
		Object.prototype.aaaa = () => {

		}
		console.dir(Object.prototype.aaaa);
		const obj = {
			a: 1,
			b: 2,
			[Symbol.iterator]() {
				let length = Object.keys(obj).length
				let index = 1
				return {
					next() {
						const now = index
						console.log({
							done: now > length,
							value: now
						});
						index++
						return {
							done: now > length,
							value: now
						}
					}
				}
			}
		}
		for (const a of obj) {
			console.log(a);
		}
		for (const key in obj) {
			console.log(key);
		}
	</script>
</head>

<body>

</body>

</html>